It's a variant of the iron armor set and has similar base attributes, however what makes it superior is it benefits from the Daedric Smithing perk which vastly improves its armor rating when upgraded and it is slightly lighter than other iron armor pieces. This makes it comparable with some of the higher tier armors. In addition, it does not include a shield as part of the set. However, what makes it relatively rare is due to the fact that it cannot be obtained from fallen draugr or crafted under normal circumstances.
The entire set can only be crafted at the Skyforge once the Companions main questline has been completed and Eorlund Gray-Mane has been spoken to about the forge. The armor is displayed in the Daedric section of the crafting list because the armor benefits from the Daedric Smithing perk, which doubles the improvement. All pieces can be upgraded with an iron ingot at a workbench. [Source: wikia]
You can download the the papercraft model here: The Elder Scrolls V: Skyrim – Male Daedric Armor Free Papercraft Download [Helmet - 13 inches] [Arms - 25 inches] [Torso - 14 inches] [Boots - 17 inches]